Remote logger for boat/rv. Voltage, temp and gps - Tips on how to do it

Hello guys.

So a family member bought a sailboat. This got me thinking, i could finally use it to make some sort of logger.

I was thinking about using arduino with SIM* gprs/gps and few sensors.
I am quite familiar with arduino, but will need some advice on the SMS/GPS.

First question is, what SIM module to use?
Something small with small footprint. I was thinking of SIM800, but then i wanted to get GPS, so i thought about SIM5320, but it seems quite expencive.

Perhaps SIM808? It has GPS and GPRS. I’m hoping someone could link me a good and working breakout with antennas. But without any 3.5mm jacks or other nonsense :slight_smile:

Or perhaps some other module? Main requirements are small size and easy to use.

Then powering it all. Since this will be battery operated, i’m guessing i need a FET or something to power on/off the radio?
Basically use software to wake up the radio, do its magic and power it off.

Its a 12V system, and they all seem to need 5V, so i need to regulate 12-14V for the arduino/GPS. Any ideas for a small SMPS with 5V output? Linears tend to get hot, and have bigger quiescent current?

For voltage readouts, im guessing voltage divider is the easiest.
Temperature DHT22 or DS18B20, no biggie.
If possible, i want current readouts. Solar panel charging, so ill be wanting to see remotely if im charging or losing power. Anything better than ACS712?

Start with an easy one, what SIM module to use?

Here is a diagram of the idea http://puu.sh/wG2eL/adafc676d4.png

And here is an example board for SIM808 http://www.ebay.co.uk/itm/171942599499 - not sure if i like the JST connection.